I never even heard of these, I would have killed for them when I was a kid, I had loads of these though:

Even though it was pretty tame Famous Five style storylines there was something kind of unsettling about reading them, you'd have a really uneasy feeling when you were flicking forward to your decision, some of them really disturbed me as a kid, until I started reading my brothers Richard Laymon stuff which was genuinely terrifying when you were young, but also great wanking material back before the internet.

Must have rented dozens of them from the local library in those pre-adolescent years. In fact, I even remember my and my mate at primary school trying to make our own version, lots of fun.

The only one I ever owned, though, was called Trial of Champions, or something like that, was a bit Gladiator-esque. The cat pissed on it once, but I liked it so much I kept it anyway. It smelled pretty rank, though.